* The Coriolis Effect: Tornadoes are formed by the interaction of strong thunderstorms and the Coriolis effect. This effect is caused by the Earth's rotation, and it deflects moving objects (like air) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

* No Deflection at the Equator: At the equator, the Coriolis effect is effectively zero. This means there is no force to cause the rotation of air masses that is necessary for tornado formation.

In summary: Without the Coriolis effect to initiate rotation, tornadoes cannot form at the equator.